Barometer



Dec. 17, 1963 A. E. JACOBSEN BAROMETER Filed Oct. 3, 1960 ilnited States This invention relates to barometers as used for the measuring and indicating or" atmospheric pressure. More particularly, the invention has to do with improvements in liquid barometers of reduced height by reason of use of a pluraiity of shortened mercury and reading tubes, and by use oi a plurality of immiscible liquids of different specific gravity and color, one of which is mercury.

Oune of the principal objects of this invention is to provide a barometer of materially shortened height or length by the novel dividing of the mercury column and its distribution to two or more coextensive, vertical tubes which are fractional portions of the total length of the column.

lt is also an object of the invention to provide a barometer having its pressure indicating scale divided in proportion to the lengths of the vertical mercury containing tubes and distributed along them.

Another object of the invention is to produce a barometer that is more practical, by reason of its shorter length, for its mounting in a case by use of gimbols, than are the ordinary types of barometers.

Further objects and advantages of the invention reside in the details of construction of its parts and in their assembled relationship, and particularly in the use of butyl phthalate as one of the immiscible liquids that are employed therein.

ln accomplishing the above mentioned and other objects of the invention, l have provided the improved details of construction, the preferred forms of which are illustrated in the accompanying drawings, wherein:

FIG. l is an elevation of a barometer embodied by the present invention wherein the mercury column and pressure indicating scale has been divided; the scale being distributed along eight vertical, coextensive mercury tubes, shown in FlG. l to be disposed in the same vertical plane.

FIG. 2 is an upper end View of the series of divisional portions of the barometer as arranged in circular formation.

FIG. 3 is a top view of a barometer wherein its reservoirs and cisterns are of rectangular or box form, instead of being cylindrical.

FIG. 4 is an enlarged, sectional detail of certain of the reservoirs at the left hand end of the device as shown in FIG. l.

FiG. 5 is an enlarged perspective view of one of the cisterns of the barometer with mercury and reading tube connections.

Referring more in detail to the drawings, and particularly to FIG. l: The barometer, as therein illustrated, comprises eight, coextensive divisional parts which are individually set oit in FlG. 1 by the bracketed spaces at a, b, c, d, e, y", g and lz, These separate divisional parts are alike in that each comprises a vertical mercury tube that opens at its lower end into the bottom portion of a closed mercury container or cistern, and at its upper end opens through the bottom of a closed reservoirf Each divisional portion also comprises a liquid containing tube that leads 'upwardly from the top wall of the corresponding mercury cistern, and continues upwardly and through the bottom of the closed liquid storage reservoir associated with that divisional part.

In FIG. l, the eight divisional parts of the barometer are shown in their assembled or functionally associated relationship. The eight mercury containing tubes are designated, respectively, by reference characters A, B, C, D, E,

arent @W F, G and l, and the eight liquid containing tubes, as associated therewith, are designated respectively by reference characters S, T, U, V, W, X, Y and Z. The cisterns into which the lower ends of the mercury containing tubes open are designated, respectively, by reference numerals 7.7, 1d, i9, 2t), 2l, 22, 23 and 24.

lt is further to be observed, by reference to FIG. 1, that the mercury tubes and the liquid tubes all extend to the same height or level and each opens into a closed reservoir corresponding thereto through its bottom wall; all reservoirs being of the same size and located at the same level. It is noted that mercury tube A opens into a reservoir 2 and liquid tube S opens into the lower end of a reservoir 3. Likewise, tubes B and T open into the bottoms of reservoirs 4 and 5; tubes C and U open into the bottoms of reservoirs 6 and 7; tubes D and V open into the bottoms of reservoirs 8 and 9; tubes E and W open into the bottoms of reservoirs itl and l1; tubes F and X open into the bottoms of reservoirs 12 and 13; tubes G and Y open into the bottoms ot reservoirs 14 and 15 and the tube l opens into reservoir le. Tube Z which extends up from the cistern 24 to the level of the bottom of reservoir 16, opens to atmospheric pressure at its upper end.

lt is further to be observed by the showing in FIG. l that reservoir 2 is closed to outside air and provides a vacuum chamber 2V therein; reservoirs 3 and 4 have a communicating passage Sil at their upper ends and, lik wise, the reservoirs 5 and 6, 7 and 8, 9 and 1li, ll and 12, 13 and ld, and 15 and 16, respectively, have communieating passages 51, 52, 53, 5ft, 55 and S6 joining them at their upper ends.

The graduated scale for use in reading barometric pressure is divided and distributed along the eight tubes S, T, U, V, W, X, Y and Z; it being shown that the lowest pressure reading is "22 and this reading is taken at the upper end of tube Z while the highest reading is 32 and this is taken at the lower end of tube S. Between these limits, the scale is equally divided along the several reading tubes.

The divisional designations of the scale may be marked directly on the tubes themselves or applied to a backing card designated by numeral 39 and shown in FIGS. 2 and 3 to be applied to the arrangement of tubes of the instrument. It more or less divisional parts are incorporated in the barometer, the scale readings would be changed accordingly. However, in the present instance, using the eight divisional parts, as shown, that division of the scale applied along tube Z provides for readings of atmospheric pressure from 22 to 231/4 incr es; tube Y provides for readings of pressures from 23% to 241/2 inches; tube X reads from 241/2 to 25% that section employing tube W provides for reading of presures from 25% to 27 inches; tube V provides for reading of pressures from 27 to 281/1 inches; tube U provides for reading of pressures from 281/1 to 291/2; tube T provides for readings from 291/2 to 30%; tube S provides readings from 30% to 32 inches. lt is to be observed that readings increase in a direction downwardly along each of the several tubes.

Explanatory to the invention it is to be here mentioned that each of the vertical mercury tubes A, B, C, D, E, F, G, and .l opens at its lower end into the corresponding cistern one-ninth of the distance from the ilat bottom wall to the top wall of the cistern. The upper ends of tubes A, B, C, D, E, F, G, J, S, T, U, V, W, X, and Y open into the bottoms of the corresponding reservoirs through their bottom walls, but do not project upwardly thereinto.

The mercury column of the present system is distributed to the eight vertical and parallel tubes A, B, C, D, E, F, G and I and to their cisterns 17, 18, i9, 2i), 2d, 22, 23 and 2d. Tube A opens at its upper end into the air tight vacuum chamber 2V provided by reservoir 2.

l'n the present system, three liquids are used, namely, mercury M herein shown in solid black; a second liquid H of lower specic gravity than mercury and indicated herein by the horizontal dash lines in reservoir 3 seen in FIG. 4 and a third liquid L having a still lower speciiic gravity and which is herein indicated by vertical dash lines. These separate liquids M, H and L have or are given diierent colors to make them readily distinguishable from each other.

Assuming that the tube structure has been provided as disclosed and described, the various liquids are so applied thereto that, at an atmospheric pressure of 22 inches, mercury M, lls the cisterns 17, 13, 19, Ztl, Z1, 22, 23 and 2d and also fills the corresponding tubes A, B, C, D, E, F, G, and I to their upper ends, as in FIG. 1.

Tubes S, T, U, V, W, X, Y and Z are illed with H liquid and this liquid also 1lills reservoir 15 to one-eighth its depth or height as measured from its bottom; reservoir 13 to 1A its height; reservoir 11 to 3A). its height; reservoir 9 to 1/2 its height; reservoir 7 to 5/8 its height; reservoir to 3A its height and reservoir 3 to 'Vs its height. Reservoirs 4, 6, d, 1t) 12, 14 and i6 are completely filled with L liquid, and this also completely fills the upper portions of the reservoirs 3, 5, 7, 9, 1l, 13 and 11S above the liquid H contained therein and can tiow from one reservoir to the other through the communication passages 5G, Si, 52, 53, 5d, 55 and 56.

As the atmospheric pressure increases above the `22 inch reading, it acts downwardly against the upper exposed surface of the supply of H liquid in tube Z and the column of H liquid is forced downwardly in tube Z accordingly. At an atmospheric pressure of 23% inches, the H liquid will all be orced down and out of the tube Z into cistern 2d. This causes a corresponding displacement and movement of mercury M in all mercury containing tubes and cisterns and moving it into the reservoirs into which the tubes open.

At this point it is to be called to attention that at the 22 inch reading, reservoir 15 was 1/s full of H liquid and as that is the amount of H liquid that is displaced, it yfollows that reservoir will now have no H liquid in it. However, tube Y is still full of H liquid.

All of the reservoirs are of the same volume and each holds 8 times the volume of tube Z. All of the other tubes are of the same size and volume as tube Z and therefore hold the same amount if we measure each from the top of the cistern to which it is attached.

If desired, the upper reservoirs that are identiiied by the odd integers may be made progressively smaller as their integers increase in value, so that each will just be suiiiciently large to hold the maximum amount of H liquid which it is required to hold. The same being the amount that would be allowed to rise up into it when the atmospheric pressure is only 22 inches.

it should be mentioned that in computing the capacity of these upper reservoirs that are identified by the odd integers, they should be considered as full when the H liquid level is up to the communication passages between reservoirs or even with the top of the partition that separates them from their companion reservoirs, because the H liquid must not be allowed to run over into these adjacent reservoirs.

The `cisterns must never have less than l@ of its depth filled with mercury, to insure against the H liquid bubbling up through the mercury columns.

By this arrangement of the various parts of the continuous tube system, and by use of immiscible liquids distributed in the tube system as explained, the overall height of the barometer is reduced to approximately 1A; of the length of a barometer employing a single column of mercury.

iIt the mercury column is comprised by four equal columns, its height would be approximately A and if it were divided into 2 columns, the height would be approximately 1/2 of the length of a single column of mercury. The purpose of this multiple tube system is three-fold:

First, to provide greater total length of reading scale without increasing the Overall length and second, to reduce the overall length by distributing the mercury to two or more columns. The second of these purposes is accomplished in the present invention in such a way as to keep the required number of tubes and reservoirs at a minimum; this being the third purpose.

To `illustrate this principle of minimizing the number of tubes required, reference is here made to an application for patent applied for on February 2, 1959, under Serial No. 790,445 now abandoned. In the barometer of that application, the tubes which connected each two consecutive mercury columns were made to serve only one purpose, namely to communi-cate the pressure from one mercury column to the next. Whereas, the present invention makes it serve two purposes, one being that mentioned above and the other serves as a reading column along which the graduated scale is distributed as shown in the diagram FIG. 1.

It is desired to point out that while i have illustrated the barometer of FlG. 1 as having the mercury column distributed over eight tubes, it `could likcwise be distributed over any other number of columns.

Furthermore, while l have illustrated the barometer of FIG. 1 as having the same number of reading tubes as mercury tubes, the number may be one less if desired, retaining only those which are intermediate of the mercury tubes.

If the liquid that is used between the mercury and butyl phthalate has a lower specific gravity than the butyl phthalate it will be used as the L liquid, and the butyl phthalate will be used as the H liquid.

`On the other hand, if the liquid that is used between the mercury and butyl phthalate has a greater specific gravity than the butyl phthalate, it will be used as the H liquid, and the butyl phthalate will be used as the L liquid.

The device 0f FlG. 3 is like that of FIG. 2 in all respects except as to the speciiic form of the reservoir and cisterns, which are shown to be rectangular in FlG. 3. The tube connections as well as the reservoirs and cisterns have been given the same identifying reference characters or numerals in FIG. 3 as in FIG. 1 and it is not believed necessary to further explain the use of the device.

What I claim as new is:

l. A barometer comprising a plurality of complemental, coacting divisional portions joined, in succession, each of said divisional portions comprising first and sccond air and liquid tight reservoirs, and an air and liquid. tight cistern, a mercury tube leading downwardly from the bottom of said first reservoir and opening into said cistern at a predetermined distance above its bottom, and a liquid reading tube leading from the bottom of the second reservoir and opening at its lower end into said cistern through its top wall; said second reservoir of cach divisional portion of the barometer having a lateral communication passage in its upper end portion with said first reservoir of the next succeeding divisional portion, all reservoirs of the several divisional portions being of thc same size and volume and disposed at the same horizontal level, and all cisterns being of the same size and located at the same lower level, a iirst liquid filling the cisterns and mercury tubes of all divisional portions when the atmospheric pressure is not higher than 23% inches of mercury, a second liquid of lesser specific gravity than said first liquid, filling said liquid reading tubes and partially filling said second reservoirs of their corresponding divisional portions, and a third liquid, of lesser specic gravity than said second liquid and differing in color therefrom, lilling the remaining portions of said second reservoirs and all of said first reservoirs through their communication passages therewith; said liquids being immiscible; the tirst reservoir of the irst divisional portion of 5 the barometer comprising a vacuum storage chamber and the liquid reading tube of the last divisional portion being open to atmosphere pressure.

2. A barometer according to claim 1 wherein each of the mercury tubes terminates at its lower end in the corresponding cistern at a level below that at which it will receive said second liquid when it is forced into the cistern under maximum atmospheric pressures to which the barometer may be subjected.

3. A barometer according to claim 1 wherein a graduated scale card is associated with the reading tubes of the several sections and said card has atmospheric pressure scale graduations marked thereon along the liquid tubes Referenees Cited in the ile of this patent UNITED STATES PATENTS 517,089 Woodworth Mar. 27, 1894 2,836,067 Quist May 27, 1958 FOREIGN PATENTS 35,630 Denmark Feb. 4, 1926 

1. A BAROMETER COMPRISING A PLURALITY OF COMPLEMENTAL, COACTING DIVISIONAL PORTIONS JOINED, IN SUCCESSION, EACH OF SAID DIVISIONAL PORTIONS COMPRISING FIRST AND SECOND AIR AND LIQUID TIGHT RESERVOIRS, AND AN AIR AND LIQUID TIGHT CISTERN, A MERCURY TUBE LEADING DOWNWARDLY FROM THE BOTTOM OF SAID FIRST RESERVOIR AND OPENING INTO SAID CISTERN AT A PREDETERMINED DISTANCE ABOVE ITS BOTTOM, AND A LIQUID READING TUBE LEADING FROM THE BOTTOM OF THE SECOND RESERVOIR AND OPENING AT ITS LOWER END INTO SAID CISTERN THROUGH ITS TOP WALL; SAID SECOND RESERVOIR OF EACH DIVISIONAL PORTION OF THE BAROMETER HAVING A LATERAL COMMUNICATION PASSAGE IN ITS UPPER END PORTION WITH SAID FIRST RESERVOIR OF THE NEXT SUCCEEDING DIVISIONAL PORTION, ALL RESERVOIRS OF THE SEVERAL DIVISIONAL PORTIONS BEING OF THE SAME SIZE AND VOLUME AND DISPOSED AT THE SAME HORIZONTAL LEVEL, AND ALL CISTERNS BEING OF THE SAME SIZE AND LOCATED AT THE SAME LOWER LEVEL, A FIRST LIQUID FILLING THE CISTERNS AND MERCURY TUBES OF ALL DIVISIONAL PORTIONS WHEN THE ATMOSPHERIC PRESSURE IS NOT HIGHER THAN 23 1/4 INCHES OF MERCURY, A SECOND LIQUID OF LESSER SPECIFIC GRAVITY THAN SAID FIRST LIQUID, FILLING SAID LIQUID READING TUBES AND PARTIALLY FILLING SAID SECOND RESERVOIRS OF THEIR CORRESPONDING DIVISIONAL PORTIONS, AND A THIRD LIQUID, OF LESSER SPECIFIC GRAVITY THAN SAID SECOND LIQUID AND DIFFERING IN COLOR THEREFROM, FILLING THE REMAINING PORTIONS OF SAID SECOND RESERVOIRS AND ALL OF SAID FIRST RESERVOIRS THROUGH THEIR COMMUNICATION PASSAGES THEREWITH; SAID LIQUIDS BEING IMMISCIBLE; THE FIRST RESERVOIR OF THE FIRST DIVISIONAL PORTION OF THE BAROMETER COMPRISING A VACUUM STORAGE CHAMBER AND THE LIQUID READING TUBE OF THE LAST DIVISIONAL PORTION BEING OPEN TO ATMOSPHERE PRESSURE. 